1. Field of the Invention
The present invention relates to a structure for wiring a wire harness between an automobile body and a mobile article such as a door, a seat or the like. Particularly, the structure is suitably used for portions subject to bending of the wire harness at a transition portion between an automobile body and a door, for example, in a floor wire harness wired from the automobile body to a luggage door (a door for opening and shutting a luggage compartment).
2. Description of Background Information
As shown in FIG. 5B, a floor harness 3 is wired from an automobile body 2 to a luggage compartment door 1 (hereinafter, referred to as a door 1) of an automobile. At a transition portion X, where the door 1 is opened and closed relative to the automobile body 2 side, the wire harness is fixed on the automobile body 2 by a clamp 4, fixed on the door 1 by a clamp 5, a wire harness portion 3a is bent and wired between the interval, and the wire harness portion 3a is subject to elongation during opening motion of the door 1.
Since the above-mentioned transition portion X is a portion which is viewed during opening of the door 1, a sheathing material is required to be installed from the viewpoint of protection of the electric wires from interference with a surrounding member together with the desire that the electric wires are not made visible. Accordingly, as shown in FIG. 6, a tape T has been conventionally wound upon the electric wire group by half-wrap winding to provide a sheath.
Further, a branch line (not shown) may be flexibly wired from a floor wire harness to a seat between the floor and the seat which is installed on the floor in a condition in which the seat can be moved back and forth. The branch line is bent and elongated in response to the back and forth movement of the seat, and the branch line is also sheathed by tape winding.
However, there are problems in that flexibility is lost when a tape is wound around electric wire groups by half-wrap winding, damage is apt to occur and the function as a protective material is inferior when the tape interferes with a surrounding member, and the appearance is rather unattractive.
A sheathing utilizing a corrugated tube having flexibility can be considered in place of the half-wrap winding of a tape, but there is a problem that cracking is apt to occur in the corrugated tube due to repetition of bending motion under low temperature conditions. The present inventor performed a test in which an opening and closing operation of 9000 times was carried out under a temperature condition of xe2x88x9230xc2x0 C., and at an opening and closing rate of 3 seconds per cycle. As a result, cracking of the corrugated tube occurred.
In consideration of the above-mentioned problems, the present invention was developed, and it is an object of the present invention to provide a sheathing material for a transition portion from an automobile body to a door, or a transition portion from an automobile body to a seat that is not damaged by the bending motion of the wire harness, and which is resistant to the occurrence of damage by a interfering material, as well as the occurrence of cracking at a low temperature, and further to provide a good appearance.
In order to solve the above-mentioned problems, the present invention provides a structure for wiring a wire harness between an automobile body and a mobile article. The wire harness is bent and wired between the mobile article, which is configured for movement relative to the automobile body, and is flexibly moved in accordance with the motion of the mobile article. In particular, a spiral tube, for example, made of a synthetic resin, is wound and sheathed on an electric wire group of the wire harness which is bent and wired at a transition portion between the automobile body and the mobile article.
According to one aspect of the present invention, the mobile article is a door configured to be opened and closed against the automobile body, and an outer periphery of the electric wire group of the wire harness is sheathed, at a transition portion between the automobile body and the door, with the spiral tube. Particularly, it is preferable that the transition portion of a floor harness wired from the automobile body to a luggage door is sheathed with the spiral tube.
In another aspect of the present invention, the mobile article is a seat configured to be moved relative to the automobile body, and an outer periphery of the electric wire group of the wire harness is sheathed, at a transition portion between the automobile body and the seat, with the spiral tube.
According to a further aspect of the present invention, the spiral tube is a tube obtained by preliminarily forming a narrow belt article having a width of about 10 mm and a thickness of about 1 to 2 mm which is formed of a synthetic resin material, for example of a polyethylene and the like, into a spiral shape. When the spiral tube is spirally wound on the outer periphery of an electric wire group constituting a wire harness at an interval of about 1 to 5 mm, the flexibility of the wire harness is not impaired, and appearance becomes more attractive. Further, stress is structurally not concentrated on the spiral tube even if distortion occurs during the motion of expansion and contraction, and durability is good even at a low temperature. It has been confirmed that no cracking occurs even after an opening and closing test of 9000 times by the present inventor under a low temperature in similar manner as described above. Thus, the durability is good even under the use condition at a low temperature.
In another aspect of the present invention, the electric wire group of the wire harness may be wrapped by a tape, and the spiral tube may be installed on the outer periphery of the tape to form a sheath. In this case, when the tape is not wrapped by half-wrap winding but is wrapped by about one winding, the flexibility of the wire harness can be maintained.
In other aspects of the present invention, the spiral tube may be formed of a synthetic resin material, the synthetic resin may be a polyethylene, and the spiral tube may be formed from a narrow belt of material having a width of about 10 mm and a thickness of about 1 to 2 mm.
In another aspect of the present invention, a method of protecting an electric wire group of a wire harness is provided. The method includes selecting a portion of the electric wire group that is subject to bending due to relative movement of members on which the electric wire group is mounted, winding a pre-formed spiral tube around the electric wire group to protect the electric wire group from damage while retaining flexibility of the electric wire group and providing an attractive appearance.
In further aspects of the present invention, the method may further include wrapping the electric wire group with tape prior to winding the pre-formed spiral tube around the electric wire group, and the pre-formed spiral tube may be formed from a narrow belt of material having a width of about 10 mm and a thickness of about 1 to 2 mm, and the material may be a synthetic resin, the synthetic resin may be a polyethylene.